Digital X-rays are here; why aren't you using them?

Digital imaging is here. It is cost-effective and helps dentists glean more useful information to make treatment decisions. Many more choices of digital systems are available for dentists to adopt than when the technology was introduced. The hardware is less costly than it was even one year ago, and image storage is now very inexpensive. Technical time is reduced, and no special training is required if the dentist or auxiliary has used a paralleling system. Insurance companies are gearing up to accept image files attached to claims. Why, then, are dentists not buying these systems as fast as manufacturer's can build them? This article explores that question and discusses the false assumptions behind perceived obstacles.     

Antibiotic resistance in nosocomial isolates in Scotland

In this first multi-centre study in Scotland, 1028 consecutive Gram-negative and staphylococci strains were obtained from four major teaching hospitals. E. coli was the most common organism among both intensive care units (ICUs) (39%) and non-ICU strains (46.6%). The prevalence of antibiotic resistance among E. coli was always higher in isolates from ICUs than non-ICUs: ceftazidime (14.1%, 7.2%), ceftriaxone (12.7%, 6.1%), cefotaxime (15.5%, 8.7%), cefuroxime (28.8%, 20.8%), amoxicillin plus clavulanic acid (52.2%, 38.8%) and gentamicin (7.0%, 2.8%). The highest incidences of resistance were identified among Enterobacter/Citrobacter spp. from ICUs; 43.8%, 41.7%, 45.8%, 54.2%, 87.5% and 10.4% of these organisms were resistant to ceftazidime, ceftriaxone, cefotaxime, cefuroxime, amoxicillin plus clavulanic acid and gentamicin, respectively.     

Pertussis: should we immunise neurologically disabled and developmentally delayed children?

A total of 400 children with neurological disorders were studied to ascertain whether they had been immunised against pertussis, the reasons for non-immunisation, and the "validity" of these reasons, as judged by interpretation of the recommendations of the Department of Health and Social Security. The results for this group were compared with those for a group of 400 aged matched controls. The study group had a significantly lower rate of immunisation than controls (p less than 0.01); rates for both groups fell sharply after 1975. A total of 192 study patients and 186 controls were not immunised. Those children with cerebral palsy had the lowest rate of immunisation (19%) and the highest number of valid reasons for non-immunisation (63%). Paediatricians apparently advised against immunisation in 61 (32%) of the index group but in only four (2%) of the controls. The risk of serious neurological handicap after pertussis immunisation is small and there is little evidence to support the view that underlying neurological disease predisposes a child to increased risk. The advice currently given by paediatricians may need to be reconsidered.     

Management ... working day of a health services manager

A varied day for one of the NHS's first marketing managers is in store for Christine Miles, Middlesex Hospital. A key message to get across is that marketing is not just promotion or selling: it is matching the strengths of the organisation to the unmet needs of 'customers'.     

Small cell nonkeratinizing carcinoma of the cervix associated with ACTH production.

The case of a 40-year-old woman with primary small cell carcinoma of the cervix is reported. She developed widespread metastates and florid Cushing's syndrome. Serum ACTH levels were greatly elevated and no site of production other than the tumor could be demonstrated at autopsy. The tumor cells demonstrated features characteristic of cells of the APUD series. Such cells have been demonstrated in normal cervical epithelium; it is likely that they may become malignant, giving rise to tumors with a potential to secrete polypeptide hormones. This case suggests that endocrine active "Apudomas" may arise from the uterine cervix. Certainly, patients with small cell carcinoma of the cervix should be investigated with appropriate serum assays for polypeptide hormones.     

Quantitation of motexafin lutetium in human plasma by liquid chromatography-tandem mass spectrometry and inductively coupled plasma-atomic emission spectroscopy

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) and inductively coupled plasma-atomic emission spectroscopy (ICP-AES) methods were developed and validated for the evaluation of motexafin lutetium (MLu, lutetium texaphyrin, PCI-0123) pharmacokinetics in human plasma. The LC-MS/MS method was specific for MLu, whereas the ICP-AES method measured total elemental lutetium. Both methods were fast, simple, precise, and accurate. For the LC-MS/MS method, a closely related analogue (PCI-0353) was used as the internal standard (IS). MLu and the IS were extracted from plasma by protein precipitation and injected onto and LC-MS/MS system configured with a C18 column and an electrospray interface. The lower limit of quantitation was 0.05 μg MLu mL⁻¹, with a signal-to-noise ratio of 15∶1. The response was linear from 0.05 to 5.0 μg MLu mL⁻¹. For the ICP-AES method, indium was used as the IS. The sample was digested with nitric acid, diluted, filtered, and then injected onto the ICP-AES system. Two standard curve ranges were validated to meet the expected range of sample concentrations: 0.5 to 50, and 0.1 to 10 μg Lu mL⁻¹. The LC-MS/MS and ICP-AES methods were validated to establish accuracy, precision, analyte stability, and assay robustness. Interday precision and accuracy of quality control samples were ≤6.3% coefficient of variation (CV) and within 2.2% relative error (RE) for the LC-MS/MS method, and ≤8.7% CV and within 4.9% RE for the ICP-AES method. Plasma samples from a subset of patients in a clinical study were analyzed using both methods. For a representative patient, over 90% of the elemental lutetium in plasma could be ascribed to intact MLu at early time points. This percentage decreased to 59% at 48 hours after dosing, suggesting that some degradation and/or metabolism of the drug may have occurred.     

Measurement of albumin and low molecular weight proteins in the urine of newborn infants using a cotton wool ball collection method

Objective : The aim of this study was to investigate the inter-relationship between urinary excretion of alpha-1-microglobulin (AIM), retinol-binding protein (RBP) and albumin in term and premature neonates, with urine collected into cotton wool balls and extracted by a novel method. Subjects and methods : Sixty-four infants were studied on the first day of life; 26 had been born at term (37–42 weeks gestation) and 38 prematurely (24–28 weeks n = 16, 29–36 weeks n = 22). Urine collected into cotton wool balls was analysed following a new detergent extraction method, which resulted in a recovery rate of 94–107% for albumin, AIM, RBP and creatinine. Results : Urinary protein excretion, expressed as a ratio to urinary creatinine, decreased significantly with increasing gestational age (24–28 weeks, 29–36 weeks, 37–42 weeks: albuminxreatinine ratio mg/mmol mean 96.9, 31.7, 19.3; AIM: creatinine ratio mg/mmol mean 99.3, 37.0, 7.8; RBP: creatinine ratio mg/mmol mean 16.2, 3.8, and <0.01, below the limit of detection, respectively). When results were corrected for birthweight, this gestation-associated effect was still present for A1M and RBP, but not for albumin. In premature infants there was a significant positive correlation between AIM: creatinine ratio and RBP: creatinine ratio ( r = 0.85), and also between albumin and both AIM and RBP ( r = 0.82 and 0.77). Conclusion : Increased excretion of AIM, RBP and albumin at earlier gestational ages is probably due to proximal tubular immaturity, although tubular damage and also glomerular dysfunction cannot be excluded as possible explanations.     

Persistent induction of nitric oxide synthase in tumours from mice treated with the anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid.

An anti-tumour agent 5,6-dimethylxanthenone-4-acetic acid (5,6-MeXAA) induced nitric oxide synthase (NOS) in the tumour, spleen, thymus and small intestine, but not in the lung, liver, kidney, heart or skeletal muscle in B6D2F1 mice bearing subcutaneous colon 38 tumours. This pattern of induction is distinct from that caused by agents such as endotoxin, muramyl dipeptide or Corynebacterium parvum. The induction of NOS (iNOS) in the tumour was more persistent (maximal at 3 days) than in other tissues (maximal at 12 h). Immunohistochemical staining suggested that iNOS was located in macrophages and endothelial cells within and around the tumour. Treatment with 5,6-MeXAA also caused substantial increases in plasma nitrite and nitrate (NOx) concentrations that peaked at 8-12 h after 5,6-MeXAA. The increase in plasma NOx was prevented by a NOS inhibitor N-iminoethyl-L-ornithine (L-NIO), indicating that it was due to enhanced production of NO. Tumour-bearing mice were more responsive than controls to 5,6-MeXAA both in their plasma NOx increase and in their lower maximally tolerated dose. L-NIO was unable to prevent the complete tumour necrosis and regression caused by 5,6-MeXAA at a dose that substantially inhibited the increase of plasma NOx. In conclusion, the experimental anti-tumour agent 5,6-MeXAA induced NO synthesis in tumour-associated macrophages and in immunologically active tissues in parallel with its effects on tumour growth. The experiments with a non-selective NOS inhibitor L-NIO, however, suggest that NO is not a significant component in the mechanism of the anti-tumour action of 5,6-MeXAA in this particular model.